docs: def process_features_online(self, corpus, input_features, output_path, chunk_size=1):
          """
          Process all features of the given corpus and save the processed features in a feature-container.
          The features are processed in **online** mode, chunk by chunk.
  
          Args:
              corpus (Corpus): The corpus to process the utterances from.
              input_features (FeatureContainer): The feature-container to process the frames from.
              output_path (str): A path to save the feature-container to.
              chunk_size (int): Number of frames to process per chunk.
  
          Returns:
              FeatureContainer: The feature-container containing the processed features.
          """
          feat_container = containers.FeatureContainer(output_path)
          feat_container.open()
  
          input_features.open()
  
          for utterance in corpus.utterances.values():
              sampling_rate = input_features.sampling_rate
              frames = input_features.get(utterance.idx, mem_map=True)
  
              current_frame = 0
  
              while current_frame < frames.shape[0]:
                  last = current_frame + chunk_size > frames.shape[0]
                  to_frame = current_frame + chunk_size
  
                  chunk = frames[current_frame:to_frame]
  
                  processed = self.process_frames(chunk, sampling_rate, current_frame,
                                                  last=last, utterance=utterance, corpus=corpus)
  
                  if processed is not None:
                      feat_container.append(utterance.idx, processed)
  
                  current_frame += chunk_size
  
          tf_frame_size, tf_hop_size = self.frame_transform(input_features.frame_size, input_features.hop_size)
          feat_container.frame_size = tf_frame_size
          feat_container.hop_size = tf_hop_size
          feat_container.sampling_rate = input_features.sampling_rate
  
          feat_container.close()
  
          return feat_container